[docs]defwaist_approximation_limit(self):""" The minimal waist for which the gauss beam approximation is valid. The gauss beam is a solution to the paraxial equation. For curvatures that are too great it is not a valid approximation. Examples ======== >>> from sympy.physics.gaussopt import BeamParameter >>> p = BeamParameter(530e-9, 1, w=1e-3) >>> p.waist_approximation_limit 1.06e-6/pi """return2*self.wavelen/pi#### Utilities###